Various conditions can damage the myocardium and, in turn, such damage can alter electrical conduction of intrinsic and artificial myocardial stimuli. For example, ischemia can cause myocardial scarring that slows electrical conduction of a pacing stimulus or myocardial depolarization responsive to a pacing stimulus. Hence, after ischemia, a scar may delay depolarization of the myocardium responsive to a pacing stimulus. In this example, a cardiac electrogram may exhibit an increased time interval between delivery of the stimulus and onset of an evoked response or peak of an evoked response. Scarring also occurs when a foreign material such as a pacing lead is introduced into the body. For example, scar tissue at an LV lead can affect characteristics of a cardiac electrogram.
As described herein, various exemplary techniques optionally use one or more paced propagation delays to optimize cardiac pacing, especially where myocardial damage may impair an ability to use one or more alternative optimization techniques.